It is well-known in the art that electronic devices which generate signals operating at high frequency (i.e., fast periodic signals or signals with fast transitions) disperse electromagnetic radiation as a natural byproduct. In some applications the electromagnetic radiation is tolerable, and thereby ignored. In other applications, however, radiation can cause signal distortion within the circuitry of a selective call unit to the extent that a unit malfunction may result. Additionally, unabated radiation may in some instances violate EMI regulations of the FCC (Federal Communications Commission).
Presently, prior art systems use, for example, a metallic shielding process for encapsulating electronic devices as a method for attenuating harmful electromagnetic radiation. Typically, a metallic shielding process involves either the drawing or forming of metal covers which are then used to encapsulate the electronic device. The cost of drawing or forming metal covers with die machines and/or cutters is an expensive manufacturing process. In many instances, the assembly process for installing metal covers on an electronic device is not accurate. As a result, intolerable levels of radiation may remain.
These disadvantages in the prior art are exacerbated when shielding is required for an entire PCB (printed circuit board), due to high-speed signals routed throughout the PCB that radiate intolerable levels of EMI. Shielding large PCB's requires substantially larger metallic covers, which are yet more difficult to seal during assembly. As a result of these limitations in the prior art, manufacturing throughput is generally slow and costly.
Accordingly, what is needed is an apparatus that functionally performs the intended functions of the prior art, and that overcomes the foregoing disadvantages described.